[ios] Adds code to support the iOS Handoff feature.

ios/chrome/browser/pref_names.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ios/chrome/browser/pref_names.h"
 
 namespace prefs {
 
 // The value to use for Accept-Languages HTTP header when making an HTTP
 // request.
@@ skipping 46 matching lines @@
 // Prefs for persisting HttpServerProperties.
 const char kHttpServerProperties[] = "net.http_server_properties";
 
 // Preference that keep information about where to create a new bookmark.
 const char kIosBookmarkFolderDefault[] = "ios.bookmark.default_folder";
 
 // Preference that hold a boolean indicating if the user has already dismissed
 // the bookmark promo dialog.
 const char kIosBookmarkPromoAlreadySeen[] = "ios.bookmark.promo_already_seen";
 
-// Whether Chrome should attempt to hand off the current URL to other Apple
-// devices that share an iCloud account.
-const char kIosHandoffToOtherDevices[] = "ios.handoff_to_other_devices";
-
 // Whether the user has enabled the Physical Web feature to surface URLs
 // broadcast by nearby devices.
 const char kIosPhysicalWebEnabled[] = "ios.physical_web_enabled";
 
 // True if the previous session exited cleanly.
 // This can be different from kStabilityExitedCleanly, because the last run of
 // the program may not have included a browsing session, and thus the last run
 // of the program may have happened after the run that included the last
 // session.
 const char kLastSessionExitedCleanly[] =
@@ skipping 56 matching lines @@
 // authorization alert.
 const char kOmniboxGeolocationLastAuthorizationAlertVersion[] =
     "ios.omnibox.geolocation_last_authorization_alert_version";
 
 // Integer which contains the timestamp at which the "Rate This App" dialog was
 // last shown.
 const char kRateThisAppDialogLastShownTime[] =
     "ios.ratethisapp.dialog_last_shown_time";
 
 }  // namespace prefs